1. Field of the Invention
The present invention generally pertains to the art of construction systems and, more particularly, to a construction system constituted by connectors and rods which can be interconnected to form various latticework structures.
2. Discussion of Prior Art
Construction systems using rods and connectors to form latticework structures are generally known in the prior art. These structures are generally created by interconnecting the ends of elongated rods to form a rigid frame. Examples of such structures include oil derricks, antenna towers, bridges and tressels.
Much of the prior art describes the methodology of constructing buildings. For example, U.S. Pat. No. 2,682,235 to Fuller discloses a geodesic dome formed from a number of struts which are interconnected by connectors. These struts and connectors are assembled into triangles which are then interconnected to form the dome. U.S. Pat. No. 2,986,241 discloses a building made using a strut and connector construction system. U.S. Pat. Nos. 3,974,600 and 5,155,951 describe how special classes of framework elements can be used to create certain types of building structures. In essence, these patents disclose using rods and connectors to make modular frame units such as triangles or polyhedrons. These modular shapes are then combined to form an overall building. Unfortunately, none of these patents disclose an inexpensive way of connecting the rods in a quick and efficient manner without the need for complex tools.
It is also known in the prior art to use connectors and rods to create toy construction sets. U.S. Pat. Nos. 1,113,371, 1,198,263 and 1,915,835 to Pajeau and U.S. Pat. No. 5,049,105 to Glickman exemplify such toy construction sets. It will be noted from observing the aforementioned patents that these patents disclose construction systems in which rod members are connected to and extend radially outward from a hub. They are limited in that all the connecting rods except one must be in a single plane. These construction sets therefore have limited application.
Several prior art patents disclose the specific structure of joining a hub to a rod. In general, these patents describe connector and rod assemblies which can be used to make many of the structures discussed above. However, it should be noted that the combination of a high degree of specialization, the relatively complex design and the difficulty of fabricating these patented connectors has evidently mitigated against their commercial success. For example, U.S. Pat. No. 4,521,998 discloses a universal hub specifically designed for geodesic type structures. U.S. Pat. No. 4,650,361 discloses a joint specifically adapted to attach reflector panels to a truss support structure of a radio telescope. U.S. Pat. Nos. 4,065,220 and 4,904,108 each disclose connectors for a construction system which are rather complex in shape and require the machining of numerous sockets at angles carefully calculated in three dimensions. Obviously, these factors add great expense in the overall manufacturing of these connectors.
U.S. Pat. Nos. 3,521,421 and 4,136,948 each disclose connectors for joining tubular members. It should be noted that while U.S. Pat. No. 3,521,421 does disclose an adjustable connector which can create a lattice, this patent does not disclose a system in which it is possible to combine several connectors to form a single rigid joint. In addition, three or more connectors of the art disclosed in U.S. Pat. No. 3,521,421 can be combined with one another in a single joint only when adjusted identically. This severely limits the possible applications of the connectors. The connection arrangement in U.S. Pat. No. 4,136,984 suffers from a similar problem. Actually, it is not possible to combine two or more of the connectors disclosed in U.S. Pat. No. 4,136,948 to form a single rigid joint. Rather, this prior art patent teaches providing a rigid, integrally formed connector for each joint that is desired. Creating a separate, rigid and integrally formed connector for each joint unduly adds to the expense associated with such a system.
Based on the above discussion, it should be readily apparent that there exists a need in the art for a construction system composed of a relatively few number of connector pieces that can be inexpensively manufactured and yet can be interconnected to form a wide variety of latticework structures.